Method and device for enamelling the edges of sanitary articles

ABSTRACT

An enamel flux supplied by a sieve carried by an articulated support is discharged under gravity onto the edge of a displaceably mounted sanitary article such as a bath or washbasin in such a manner as to form a projecting portion which is turned-down against the lateral surface of the edge by means of a jet of gas which is directed transversely by a positionallyadjustable nozzle.

United States Patent Primault Sept. 9, 1975 METHOD AND DEVICE FOR ENAMELLING 2,129,471 9/l938 Juengst 1, 239/587 THE 0F SANITARY 2,139,628 l2/l938 Terry 239/587 2,288,101 6/1942 Mayer n 239/587 [75] Inven r: An r Primault, Garches, France 2,986,336 5/1961 Sharkey 239/537 [73] Assignee: Societe Generale de Fonderie, Paris,

France Primary ExaminerLloyd L. King [22] Filed, May 18 1973 Attorney, Agent, or FirmYoung & Thompson [2l] Appl. No: 361,608

[57] ABSTRACT [30] Foreign Application Priority Data J 27 1972 F 72 23187 An enamel flux supplled by a sieve carried by an artlcrance ulated support is discharged under gravity onto the edge of a displaceably mounted sanitary article such 3? as a bath or wash-basin in such a manner as to form a i /4 projecting portion which is turned-down against the le 0 can lateral surface of the edge by means of a jet of gas which is directed transversely by a positionally- [56] References Cited adjustable nozzle" UNITED STATES PATENTS 525,487 9/1894 Crawford 239/587 13 Claims, 6 Drawing Figures 1 I l L PATENTED 9W5 3,904,128

sum 1 [1F 3 METHOD AND DEVICE FOR ENAMELLING THE EDGES OF SANITARY ARTICLES This invention relates to a method and a device for enamelling edges of sanitary articles such as baths, wash-basins and the like.

A known method of enamelling articles of this type is carried out in the dry state by deposition of enamel powder on the object to be enamelled which has previously been heated to a temperature above the melting temperature of the enamel. When coming into contact with the object, the enamel melts and forms a coating which hardens during cooling of the object.

It is endeavored in practice to place the surface of the object in a position close to the horizontal in order to receive the enamel powder which is deposited in a layer by means of a dusting device such as a sieve. The grains of enamel thus come into contact with the surface of the article in a direction which is substantially at right angles to said surface. Said grains then melt immediately without sliding over the article considered and this is conducive to uniform thickness of the enamel coating.

This method is also carried out by means of other known devices such as those described in particular in French Pat. Nos. 1,590,113 of Apr. 12th, 1968 and 69,31,154 of Sept. 12th, 1969 in the name of the pres ent Applicant.

In point of fact, the edge of sanitary articles and especially baths usually has a lateral surface which is joined to the remainder of the edge by a rounded surface. This lateral surface must be coated with enamel to the same extent as the remainder of the edge.

In practice, said lateral surface is enamelled at the same time as the remainder of the edge but it cannot in that case be presented at right angles to the jet of enamel powder.

Irregularities consequently occur in the distribution of enamel and these affect the quality of the finished article.

The method of enamelling to which the present invention is primarily directed makes it possible to obtain articles which do not exhibit these imperfections.

In accordance with the invention, the method for enamelling the edges of sanitary articles such as baths in which the vicinity of the edge to be coated is dusted with enamel is characterized in that an enamel flux is permitted to fall onto the edge so as to project therefrom and that the projecting portion of said flux is turned down towards the lateral surface of the edge by blowing towards said edge ajet of gas which is directed transversely with respect to said lateral surface.

The blast thus produced has the effect of directing the enamel powder towards the lateral surface along a path having a velocity component which is perpendicular to said surface, thereby preventing the powder from sliding thereon and ensuring uniform distribution.

In a preferred embodiment of the method, the jet of gas is blown through a nozzle and the flow velocity of said jet is regulated as a function of the distahce be tween the outlet of the nozzle and the surface to be enamelled.

By reason of the irregularity of the contour of some sanitary articles, the distance between the nozzle outlet and the surface to be enamelled can in fact vary during the rotation of the article. In the case of articles of this type, it can accordingly be an advantage to increase or decrease the gas flow rate during the enamelling operation according as the nozzle outlet is located at a greater or smaller distance from the surface to be enamelled.

The grains of enamel powder thus come into contact with the article at a constant velocity, thereby improving the quality of the enamel coating to an even greater extent.

The invention is also directed to a device for carrying out said method. Said device comprises a support for an enamel-dusting unit and means for adjusting the position of said unit with respect to the article to be enamelled.

In accordance with the invention, said device is characterized in that it comprises a blowing nozzle which is placed with respect to the support so that the axis of said nozzle intersects or passes in the vicinity of the vertical center-line of the dusting unit, and means for producing a gas stream within the nozzle.

The gaseous fluid is preferably air which is blown into the nozzle by a fan and the nozzle is located beneath the dusting-unit support. It is thus possible to turndown the projecting portion of the enamel flux against the lateral surface of the edge.

In a preferred embodiment, the device comprises means for adjusting the angular position of the nozzle with respect to the dusting-unit support.

The nozzle can thus be brought to the appropriate position with respect to the article to be enamelled and withdrawn after the edge of said article has been enamelled, the air-blast being then discontinued.

In another advantageous embodiment, the device comprises means for regulating the flow rate of gaseous fluid as a function of the distance between the nozzle outlet and the surface to be enamelled.

Said regulating means preferably comprise a diaphragm having a variable aperture and make it possible to maintain the velocity of the enamel powder at a substantially constant value at the time of impact of said powder on the lateral surface of the article.

Further properties and advantages of the invention will become apparent from the detailed description which is given hereinafter, reference being made to the accompanying drawings which are given by way of example and not in any limiting sense, and wherein:

FIG. 1 is a diagram of one embodiment of the invention as applied to the enamelling of a bath;

FIG. 2 is a fragmentary top view to a larger scale showing the embodiment of FIG. 1;

FIG. 3 is a sectional view to a larger scale showing the means for regulating the gas flow, this view being taken along line III-III of FIG. 4;

FIGS. 4 and 5 are views in side elevation showing the regulating means of FIG. 3;

FIG. 6 shows the respective paths followed by the enamel powder and the gas jet in the vicinity of the edge to be enamelled.

The embodiment which is shown in FIGS. 1 and 2 comprises a support for a dusting unit constituted by a sieve 5 as has already been disclosed in the above-cited French Pat. No. 1,590,113. Said support comprises an articulated and deformable frame 1 and a turret 3. The supporting frame 1 comprises a boom 2 which is pivotally mounted on the turret 3 and a fore-boom 4 which carries the sieve 5. The turret is mounted on a base 6 so as to be capable of rotation about its axis X-X'.

The sieve 5 is carried by an arm 7 on which is fixed a vibrator 8, although other means can evidently be provided for dusting the enamel. A balance-weight 9 is fixed at the extremity of the extension of the boom 2. The support for the sieve 5 is such that this latter remains continuously in a substantially horizontal position.

In accordance with the invention, a blowing nozzle 11 is pivotally mounted on the turret 3 and connected to means described hereinafter for producing a gas stream which passes through said nozzle.

ln the example herein described, the sanitary article to be enamelled is a bath 12 which is placed horizontally on an orientable table of known type as represented diagrammatically at 41. Said table is capable of carrying out movements of rotation about a vertical axis and movements of horizontal translation so that the entire edge 13 of the bath 12 and its external lateral surface 14 passes beneath the sieve 5.

The bath-supporting table 41 can advantageously be of the type described in French Pat. No. 69,08,838 of Mar. 26th, 1969 in the name of the present Applicant.

The nozzle 11 is equipped with a fan 15 (shown in FIG. 2) for blowing gas and is pivoted on the turret 3 about a substantially horizontal pin 17. The fan 15 is of the impeller type, for example.

Said nozzle 11 is so arranged with respect to the turret 3 and the supporting frame 1 that the axis YY of said nozzle intersects the vertical axis Z-Z of the sieve 5 or passes in the vicinity of this latterv The gas which is blown into the nozzle is preferably air but another gas such as nitrogen can be employed without departing from the scope of the invention.

The angular position of the base 11 with respect to the support frame 1 which carries the sieve 5 is adjustable by means of a jack 18 which is mounted in the same manner as a strut and pivotally connected at one end to the nozzle 11 and at the other end to the base of the turret 3.

The nozzle 1 1 is in the top position when the operating rod 19 of the jack 18 is in the outwardly extended position whereas said nozzle is in the bottom position 11a when the operating rod 19 is withdrawn. In this example, the angle between the two end positions of the nozzle 11 is approximately 30.

Means are provided for regulating the flow rate of the gas which is blown through the nozzle 11. Said means comprise an iristype diaphragm 16 which is mounted at the inlet of a duct 23 through which air is admitted into the nozzle 11. The aperture of said diaphragm can be adjusted manually by means ofa control knob 22 (as shown in FIG. 2). The means considered further comprise a circular butterfly-gate 24 which serves to control the air flow rate and is placed within the duct 23 between the diaphragm l6 and the fan 15.

Referring more particularly to FIGS. 3 to 5, it is apparent that said butterflygate 24 is mounted diametrically on a rotary positioning rod 25 which is placed transversely with respect to the duct 23.

The butterfly-gate 24 is fixed to said rod 25 by means of two screws 60; a cord 28 is wound around one end of said rod 25 and connects this latter to a sliding arma ture 27 located within the air-gap of an electromagnet 26 which is fixed on an annular flange 40 of the duct 23.

The cord 28 is preferably formed of plastic material and the electromagnet 26 is connected by means of leads 50 to a current supply which is not shown in the drawings.

The armature 27 is capable of sliding within the electromagnet 26 when this latter is energized and of caus ing the rod 25 and the butterfly-gate 24 to rotate by means of the connecting cord 28.

A cam 66 is rigidly fixed for rotation at one end of the rod 25 and is maintained by a spiral spring 65 against a fixed stop 67 which is mounted on the duct 23.

The spring 65 is placed around the rod 25 at that end of this latter which is remote from the cam 66 and is applied against the body of the duct 23 by a screw 71 to which is attached the end 65a of the spring 65.

A circular sector 68 (as shown in FIG. 5) having a cavity 69 is placed opposite to the cam 66 with respect to the rod 25. Said sector 68 is held in position by a bolt 70 which is passed through the cavity 69 and screwed into the wall of the duct 23, that extremity 68a of said sector 68 which is remote from the fixed stop 67 being intended to serve as an adjustable stop for the cam 66.

In order to limit the rotation of the cam 66 and therefore 0f the butterfly-gate 24, it is only necessary to unscrew the bolt 70 and to cause the sector 68 to rotate until the desired position is reached by bringing the extremity 68a closer to the cam 66.

As is apparent from FIG. 5, it is thus possible to limit the rotation of the cam 66 to a maximum angle of this value corresponds to complete closure of the duct 23 by the butterfly-gate 24.

In the example which is illustrated, the edge of the bath 12 has a lateral surface 14, the width of which is l to 2 cm approximately, depending on the type of bath.

The distance between said surface 14 and the outlet 21 of the nozzle 11 remains constant when the dis placement of the bath 12 corresponds to translational motion in the direction of its longest side but this distance decreases when a movement of rotation of the bath is initiated so as to bring one end of this latter into position vertically beneath the sieve 5.

On completion of a movement of rotation through an angle of 45, the bath takes up the position 12a (FIG. 2). As shown in this figure, that surface of the edge which is located beneath the sieve 5 is then much larger and the corresponding lateral surfaces are much closer to the nozzle 11.

In order to take this modification into account, the sieve 5 is moved backwards to position 5a in synchronism by manual or mechanical control means in order that the surfaces to be enamelled should be maintained vertically beneath the sieve in an accurate manner.

in accordance with one of the characteristic features of the invention, it is proposed to regulate the rate of flow of air which is blown through the nozzle 11 as a function of the distance between the outlet orifice of said nozzle and the surface 14 to be enamelled, said rate of flow being intended to vary in direct proportion to the distance. This adjustment can be performed by hand but is preferably carried out automatically. lnthis case, the programming unit 42 which controls the correlative displacements of the bath-supporting table 41 and the articulated frame 1 in known manner is also intended to control the excitation of the electromagnet 26. These connections are represented diagrammatically in FIGS. 1 and 2 by chain-dotted lines which start from the unit 42. There are thus shown the control connections which are established between said unit and the jack 18 as well as those which terminate at the position-control elements of the turret 3 and the articulated frame 1.

Within the field of application of the device as thus constructed, the method is carried out as follows:

Prior to commencement of the enamelling operation, the operating rod 19 of the jack 18 is withdrawn, the nozzle 11 is in the bottom position 110 and the fan is stationary.

The jack 18 is then actuated so as to bring the nozzle 11 into the service position by rotating this latter through an angle of approximately 30 about the pivotpin 17. The aperture of the diaphragm 16 is then adjusted to the appropriate value by means of the manual control knob 22. Since the electromagnet 26 is not energized, the butterfly-gate 24 is parallel to the axis of the duct 23 in the position of maximum flow.

The bath 12 is then displaced in horizontal translational motion in a direction parallel to its longest side; at the same time, an enamel flux A (as shown in FIG. 6) which is distributed by the sieve 5 is allowed to fall onto the edge 13 in such a manner as to project outwards from the bath with respect to the vertical line of extension of the lateral surface 14 of the edge 13. The fan 15 is also put into operation.

The air is drawn through the diaphragm 16 and the duct 23, then blown through the nozzle 11 onto the enamel flux A.

The gas jet B which is directed transversely with respect to the lateral surface 14 deflects the path of the projecting portion A of the enamel flux towards said surface 14. The enamel powder therefore falls onto said surface at a velocity having an appreciable horizontal component.

When the bath begins to move in rotation so that one end is brought into position vertically beneath the sieve 5, the control unit 42 energizes the electromagnet 26. Armature 27 is then displaced, the rod 25 is set in rotation and the butterfly-gate 24 partially closes the duct 23, the rotation of said rod being limited by the adjustable sector 68.

Said movement of rotation reduces the rate at which the air flows through the nozzle 11 towards the lateral surface 14a of the edge 13a.

Coating of one end of the bath 12 with enamel is completed after this latter has been rotated through an angle of 180. The bath 12 then resumes a translational movement in a direction parallel to the longest sides thereof and the edge of the second long side passes directly beneath the sieve 5.

The program of control interrupts the excitation of the electromagnet 26 and the spiral spring 65 returns the butterfly-gate 24 to its initial position. The flow rate of blown air then reverts to its maximum value.

The operations described in the foregoing are repeated when the second end of the bath 12 is brought into position beneath the sieve 5.

The aperture of the diaphragm 16 remains constant while enamelling of the entire edge of the bath is in progress.

In the case of distances between the outlet 21 of the nozzle 11 and the surface 14 to be enamelled which vary between 50 and cm, the air flow rate can vary by way of example between 200 dm per minute during enamelling of the long sides of the bath and 100 dm per minute while enamelling of the ends of the bath is taking place. The corresponding air velocities are 3 meters per second and one meter per second.

In addition and in the case of a bath of conventional shape, the top portion of the outlet 21 of the nozzle 11 can be located at a distance of approximately 35 mm below the sieve 5 and at a distance of mm above the plane of the horizontal portion of the edge 13.

The delivery of enamel is regulated in known manner by means of the vibrator 8. In the example herein described, said delivery can vary between 10 kg per minute at the beginning of the enamelling operation and 3 kg per minute at the end of the enamelling operation, the frequency of vibrations being correlatively decreased from approximately 2000 to 500 per minute.

The enamel coating which is deposited on the edge of the article by means of the method and the device according to the invention is of highly constant thickness by virtue of the uniformity of distribution of enamel over the entire periphery of the article.

The device which is provided by the invention thus permits the manufacture of sanitary articles of the high est quality. in addition, it calls solely for the use of comparatively inexpensive means by virtue of the simplicity of the method and the possibility of carrying out this latter automatically by programming.

The invention is clearly not limited to the embodiment described in the foregoing and permits alternative forms of construction, among which can be mentioned the following:

the air-flow can be permitted to remain constant during the enamelling operation, in which case it is only necessary to disconnect the electromagnet 26 whilst the butterfly-gate 24 accordingly remains in the rest position. This alternative arrangement is advantageous for articles to be enamelled which have a regular contour.

It is also possible to replace the butterfly-gate 24 and the elements for controlling this latter by an electric motor or an electromagnet for adjusting the diaphragm l6. Said motor or said electromagnet can be controlled automatically by program in synchronism with the movements of the article to be enamelled.

In the case of baths or articles having complex shapes, the angular position of the nozzle 11 can be controlled by means of a program which is synchronized with the movements of the article so as to main tain the nozzle outlet 21 at a constant height above the surface to be enamelled.

The jack 18 for adjusting the position of the nozzle 11 can be replaced by a tie-rod system which is known per se and serves to connect said nozzle 11 to the turret 3. if the displacements of the nozzle 11 along a horizontal plane are controlled in dependence on those of the articulated frame 1 in such a manner as to ensure that the distance between the outlet orifice of said nozzle and the surface 14 of the article to be enamelled remains constant, the air-flow can also be maintained at a constant value.

The nozzle 11 can be mounted on an independent support such as a carriage which is separate from the support provided for the enamel-dusting unit.

We claim:

1. A device for enamelling the edges of sanitary articles such as baths, said device comprising a movable and deformable support, a dusting unit carried by said support and comprising means to deliver powdered enamel, means to control the position in space of said dusting unit, said device further comprising a gas blowing nozzle carried by said support and so directed that the axis of said nozzle is adjacent the vertical centerline of said dusting unit and below the latter, so as to substantially intersect the flow of enamel dust, when said dusting unit is operated, and means for producing a gas stream through said nozzle toward said centerline.

2. A device as defined in claim 1 and wherein said means for producing a gas stream through said nozzle comprises an air-blowing fan on said nozzle, said device further comprising means for controlling the air-flow according to the distance between the nozzle outlet and the surface to be enamelled.

3. A device as defined in claim I, wherein the means for regulating the airflow comprise an adjustable diaphragm.

4. A device as defined in claim 3, wherein said device comprises an electric motor for adjusting the diaphragm and means for automatically controlling said motor in synchronism with the movements of the arti cle to be enamelled.

5. A device as defined in claim 3 and in which the aperture of the diaphragm is maintained constant, wherein said device comprises a butterfly-gate for controlling the airflow, said butterfly-gate being adjusted by an electromagnet which is adapted to be controlled automatically in synchronism with the movements of the article to be enamelled 6. A device as defined in claim 3, wherein said device comprises means for manual adjustment of the diaphragm.

7. A device as defined in claim 1, wherein the nozzle is pivotally mounted on a horizontal pin of the support provided for the enamel-dusting unit.

8. A device as defined in claim 1, wherein the nozzle is mounted on an independent support which is separate from the support provided for the enamehdusting unit.

9. A device as defined in claim 7, wherein the support provided for the enamel-dusting unit comprises a rotary turret on which is mounted a deformable articulated frame adapted to carry the nozzle, wherein the means for adjusting the angular position of said nozzle comprise a jack mounted on said turret.

10. A device as defined in claim 1, wherein said device comprises means for automatically controlling the angular position of the nozzle in synchronism with the movements of the article to be enamelled.

11. An installation for enamelling by powder dusting the edges of sanitary articles such as baths, said installation comprising a displaceable table arranged to support a said sanitary article, a movable and deformable support laterally mounted with respect to said table, a dusting unit carried by said support and comprising means to deliver powdered enamel, means to control the position in space of said dusting unit, said device further comprising a gas blowing nozzle carried by said support and so directed that the axis of said nozzle is adjacent the vertical centerline of said dusting unit and below the latter, so as to substantially intersect the flow of enamel dust when said dusting unit is operated, and means for producing a gas stream through said nozzle toward said centerline, said installation further comprising means for controlling the angular position of said nozzle relative to said support.

12. An installation, as defined in claim 11, said installation comprising means for automatically controlling the angular position of said nozzle in synchronism with the instantaneous position of said bath supporting table.

13. A device as defined in claim 3, wherein said device comprises an electromagnet for adjusting the diaphragm, and means for automatically controlling said electromagnet in synchronism with the movements of the article to be enamelled. 

1. A device for enamelling the edges of sanitary articles such as baths, said device comprising a movable and deformable support, a dusting unit carried by said support and comprising means to deliver powdered enamel, means to control the position in space of said dusting unit, said device further comprising a gas blowing nozzle carried by said support and so directed that the axis of said nozzle is adjacent the vertical centerline of said dusting unit and below the latter, so as to substantially intersect the flow of enamel dust, when said dusting unit is operated, and means for producing a gas stream through said nozzle toward said centerline.
 2. A device as defined in claim 1 and wherein said means for producing a gas stream through said nozzle comprises an air-blowing fan on said nozzle, said device further comprising means for controlling the air-flow according to the distance between the nozzle outlet and the surface to be enamelled.
 3. A device as defined in claim 1, wherein the means for regulating the airflow comprise an adjustable diaphragm.
 4. A device as defined in claim 3, wherein said device comprises an electric motor for adjusting the diaphragm and means for automatically controlling said motor in synchronism with the movements of the article to be enamelled.
 5. A device as defined in claim 3 and in which the aperture of the diaphragm is maintained constant, wherein said device comprises a butterfly-gate for controlling the airflow, said butterfly-gate being adjusted by an electromagnet which is adapted to be controlled automatically in synchronism with the movements of the article to be enamelled.
 6. A device as defined in claim 3, wherein said device comprises means for manual adjustment of the diaphragm.
 7. A device as defined in claim 1, wherein the nozzle is pivotally mounted on a horizontal pin of the support provided for the enamel-dusting unit.
 8. A device as defined in claim 1, wherein the nozzle is mounted on an independent support which is separate from the support provided for the enamel-dusting unit.
 9. A device as defined in claim 7, wherein the support provided for the enamel-dusting unit comprises a rotary turret on which is mounted a deformable articulated frame adapted to carry the nozzle, wherein the means for adjusting the angular position of said nozzle comprise a jack mounted on said turret.
 10. A device as defined in claim 1, wherein said device comprises means for automatically controlling the angular position of the nozzle in synchronism with the movements of the article to be enamelled.
 11. An installation for enamelling by powder dusting the edges of sanitary articles such as baths, said installation comprising a displaceable table arranged to support a said sanitary article, a movable and deformable support laterally mounted with respect to said table, a dusting unit carried by said support and comprising means To deliver powdered enamel, means to control the position in space of said dusting unit, said device further comprising a gas blowing nozzle carried by said support and so directed that the axis of said nozzle is adjacent the vertical centerline of said dusting unit and below the latter, so as to substantially intersect the flow of enamel dust when said dusting unit is operated, and means for producing a gas stream through said nozzle toward said centerline, said installation further comprising means for controlling the angular position of said nozzle relative to said support.
 12. An installation, as defined in claim 11, said installation comprising means for automatically controlling the angular position of said nozzle in synchronism with the instantaneous position of said bath supporting table.
 13. A device as defined in claim 3, wherein said device comprises an electromagnet for adjusting the diaphragm, and means for automatically controlling said electromagnet in synchronism with the movements of the article to be enamelled. 